SN74LS221DR

Overview

The SN74LS221DR is a dual non-retriggerable one-shot monostable multivibrator manufactured by Texas Instruments. It operates within the 74LS logic series and features two independent circuits in a 16-SOIC package. The device supports a supply voltage range of 4.75 V to 5.25 V and functions at temperatures between 0°C and 70°C. Key electrical parameters include a propagation delay of 45 ns, a high-level output current of 400 µA, and a low-level output current of 8 mA.

Feature Summary

• Provides two independent non-retriggerable monostable multivibrator circuits for generating fixed-width pulses.
• Includes complementary outputs for each circuit to support diverse signal processing requirements.
• Features an integrated clear function to reset the timing cycle immediately upon activation.

Applications

• Timing pulse generation in digital systems
• Debouncing mechanical switches
• Frequency division circuits

Procurement Notes

Verify that the component matches the SN74LS221DR designation from Texas Instruments. Confirm the 16-SOIC surface-mount package and 74LS logic family specifications. Ensure compliance with RoHS3 standards and check the operating temperature range against application requirements before procurement.

Selection Notes

Select this component when dual independent monostable functionality is required in a compact surface-mount form factor. Consider the 45 ns propagation delay and standard TTL-compatible drive currents. Verify that the 74LS power consumption characteristics align with system thermal constraints compared to faster or lower-power alternatives.

Part Context

This part belongs to the Texas Instruments 74LS series of logic devices. It is the SOIC variant of the SN74LS221, which is a dual non-retriggerable one-shot. The device is designed for general-purpose timing applications requiring reliable pulse generation with complementary outputs.

Replacement Considerations

SN74LS221N (Texas Instruments) offers identical functionality in a PDIP-16 through-hole package. CD74HCT123E (Texas Instruments) serves as a similar alternative but utilizes HCT logic technology.